Re: How can I force updating mini window's header line when mode line is updated?

[Amos Bird <amosbird@gmail.com>]

Thanks!

Um I'm afraid post-command-hook might not help here. Emacs code 
has deep assumption of mini window having only one line. After I 
turn on the header line, things become messy. I'll try collecting 
all the hard-coded logic and see if this route indeed works.

Here is what I've achieved so far 
https://la.wentropy.com/WYjq.webm

regards,

Stefan Monnier <monnier@iro.umontreal.ca> writes:

>> 3. (setq-default header-line-format mode-line-format)
>
> Hmm... this would put a header-line on all windows, whereas IIUC 
> you
> want a header-line only for the mini-window, right?
>
>> However the header line doesn't get updated at all.
>
> A window's header-line (and mode-line) will normally only be
> updated if something happens in this window that would require
> updating it.  Part of this detection of when update is needed is
> automatic, tho not all of it (so Elisp code sometimes has to 
> call
> force-mode-line-update).
>
> In your case, the header-line belongs to the mini-window, so 
> this
> detection (and most of existing Elisp code calling
> force-mode-line-update) won't help because it will only detect a 
> need
> for update when the *mini-window* is affected, whereas you most 
> likely
> want to update it in many other cases.
>
> So you'll probably want to add some `post-command-hook` (and/or 
> other
> related hooks) to try and detect when an update is needed, at 
> which
> point you'll need to do
>
>     (with-current-buffer <mini-window-buffer> 
>     (force-mode-line-update))
>
>> It seems xdisp.c only
>> provides ways to update mode line, and I've reached the limit 
>> of my
>> emacs-fu. How can I achieve this without hacking tons of the 
>> display logic?
>
> AFAIK the redisplay doesn't really distinguish the mode-line 
> from the
> header-line in this respect (e.g. force-mode-line-update will 
> cause both
> the mode-line and the header-line to be refreshed).
>
>
>         Stefan


--
Amos Bird
amosbird@gmail.com